1. Field of the Invention
The invention is in the field of the vacuum distillation of sponge refractory metals, such as zirconium and/or hafnium and titanium, and of furnaces for accomplishing the same.
2. Description of the Prior Art
In the production of zirconium and/or hafnium metals, vacuum distillation is conventionally applied to the sponge metal produced by reduction of the metal tetrachloride with magnesium so as to remove both unreacted magnesium and the magnesium chloride produced during the reaction. This is normally done as a batch operation in a single furnace crucible with the furnace temperature raised as required to effect vaporization of the unreacted magnesium and of the magnesium chloride during respective time periods to accomplish removal of these contaminants from the sponge metal product.